Statistical Study of ICMEs with Low Mean Carbon Charge State Plasmas Detected from 1998 to 2011

Feng, Xuedong; Yao, Shuo; Li, Dongni; Li, Gang; Yan, Xiaoli

doi:10.3847/1538-4357/aae92c

Cited by 9 publications

(11 citation statements)

References 52 publications

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“…The work reported that magnetic clouds exhibit higher ionic charge states than non-magnetic clouds. In addition, statistical results demonstrated that fast magnetic clouds have higher charge states and relative elemental abundances (except the C/O) than slow ones (Owens, 2018;Huang et al, 2020), and cold prominence plasmas with lower charge states can be detected within ICMEs near 1 au (Lepri and Zurbuchen, 2010;Gilbert et al, 2012;Sharma and Srivastava, 2012;Wang, Feng, and Zhao, 2018;Feng et al, 2018). Zurbuchen et al (2016) performed a comprehensive analysis of the elemental abundances of 310 ICMEs on Richardson and Cane's catalog from 1998 March to 2011 August (Richardson and Cane, 2010).…”

Section: Introductionmentioning

confidence: 99%

Solar Cycle Dependence of ICME Composition

Song

Sun

et al. 2021

Sol Phys

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Coronal mass ejections (CMEs) belong to the most energetic explosions in the solar atmosphere, and their occurrence rates exhibit obvious solar cycle dependence with more events taking place around solar maximum. Composition of interplanetary CMEs (ICMEs), referring to the charge states and elemental abundances of ions, opens an important avenue to investigate CMEs. In this paper, we conduct a statistical study on the charge states of five elements (Mg, Fe, Si, C, and O) and the relative abundances of six elements (Mg/O, Fe/O, Si/O, C/O, Ne/O, and He/O) within ICMEs from 1998 to 2011, and find that all the ICME compositions possess a solar cycle dependence. All of the ionic charge states and most of the relative elemental abundances are positively correlated with sunspot numbers (SSNs), and only the C/O ratios are inversely correlated with the SSNs. The compositions (except the C/O) increase with the SSNs during the ascending phase (1998–2000 and 2009–2011) and remain elevated during solar maximum and descending phase (2000–2005) compared to solar minimum (2007–2009). The charge states of low-FIP (first ionization potential) elements (Mg, Fe, and Si) and their relative abundances are correlated well, while no clear correlation is observed between the C6+/C5+ or C6+/C4+ and C/O. Most interestingly, we find that the Ne/O ratios of ICMEs and slow solar wind have the opposite solar cycle dependence.

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Section: Introductionmentioning

confidence: 99%

Solar Cycle Dependence of ICME Composition

Song

Sun

et al. 2021

Sol Phys

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“…Evidence from heavy ions, plasma moments, and the interplanetary magnetic field (IMF) were reported. The lower charge states of C, O, and Fe ions indicate the lower freeze-in ionic temperature (Lepri & Zurbuchen 2010;Song et al 2016;Kocher et al 2017;Feng et al 2018;Wang et al 2018;Rivera et al 2019). The proton density, proton temperature, and singly ionized helium support the existence of cold and dense chromospheric materials (Schwenn et al 1980;Burlaga et al 1998;Gopalswamy et al 1998;Yao et al 2010).…”

Section: Introductionmentioning

confidence: 94%

“…In this work, we select ICMEs from a list reported by Cane & Richardson (2003) and Richardson & Cane (2010). 3 The segments of PCs in ICMEs are selected from a list of carbon cold materials in Feng et al (2018). It should be noted that these carbon cold materials in ICMEs are selected by carbon mean charge and carbon ionic temperature compared to 24 hr long QSW preceding the ICME (Feng et al 2018).…”

Section: Data and Training Samplesmentioning

confidence: 99%

“…So far, the cold materials are identified by solid/relative criteria. Some of the cold materials are related to three-part CME observations (Lepri & Zurbuchen 2010;Feng et al 2018;, which are possibly parts of prominence, while some cold materials are identified in solar wind (Zhao et al 2017;. It is argued that not all cold materials are from erupted prominence.…”

Section: Introductionmentioning

confidence: 96%

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Key Signatures of Prominence Materials and Category of Cold Materials Identified by Random Forest Classifier

Cheng,

Yao,

Meng

2023

ApJS

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The origin of cold materials identified by different criteria is unclear. They are highly suspected to be erupted prominences. However, some cold materials defined by charge depletion exist in both quiet solar wind and interplanetary coronal mass ejections (ICMEs). Recently, solar observations show failed prominence eruption in coronal mass ejections (CMEs) that the prominence sometimes did not propagate into interplanetary space. This work uses Random Forest Classifier (RFC), which is an interpretable supervised machine-learning algorithm to study the distinct signatures of prominence cold materials (PCs) compared to quiet solar wind (QSW) and ICMEs excluding cold materials (ICMEEs). Twelve physical features measured by ACE at 1 au and the monthly averaged sunspot number are used in this study. The measurements from ACE are proton moments, magnetic field component B z , He/H, He/O, Fe/O, mean charge of oxygen and carbon, C6+/C5, C6+/C4+, and O7+/O6+. According to the returned weights from RFC that are checked by support vector machine classifier, the most important in situ signatures of PCs are obtained. Next, the trained RFC is used to check the category of the cold materials not related to CME observations. The results show that most segments of the cold materials are from prominences, but four of them are possibly from ICMEEs; another one segment is possibly from QSW. The most distinct signatures of PCs are lower (C6+/C5+)/(O7+/O6+), proton temperature, and He/O. Considering the obvious overlaps on key physical features between QSW, ICMEEs, and PCs, the multifeature classifier shows an advantage in identifying them than solid criteria.

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“…One of the signatures of heavy ions in ICMEs is that the average charge states are usually higher than those in the solar wind, which indicates a stronger heating process in the initiation of CMEs (Wimmer-Schweingruber et al 2006;Gruesbeck et al 2011;Henke et al 2001). Meanwhile, unusually low charge states of heavy ions in ICMEs have also been reported (Lepri & Zurbuchen 2010;Song et al 2017;Feng et al 2018), which are thought to be possibly related to the cold prominence plasma. When a CME erupts and propagates outward, the electron density decreases rapidly with solar distance.…”

Section: Introductionmentioning

confidence: 99%

Detailed composition of iron ions in interplanetary coronal mass ejections based on a multipopulation approach

Gu¹,

Heidrich-Meisner²,

Wimmer‐Schweingruber³

et al. 2023

A&A

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Context. Coronal mass ejections (CMEs) are extremely dynamical, large-scale events in which plasma – but not only the coronal plasma – is ejected into interplanetary space. If a CME is detected in situ by a spacecraft located in the interplanetary medium, it is then called an interplanetary coronal mass ejection (ICME). This solar activity has been studied widely since coronagraphs were first flown into space in the early 1970s. Aims. Charge states of heavy ions reflect important information about the coronal temperature profile due to the freeze-in effect and it is estimated that iron ions freeze in at heights of ∼5 solar radii. However, the measured charge-state distribution of iron ions cannot be composed of only one single group of plasma. To identify the different populations of iron charge-state composition of ICMEs and determine their sources, we developed a model that independently uses two, three, and four populations of iron ions to fit the measured charge-state distribution in ICMEs detected by the Advanced Composition Explorer (ACE) at 1 AU. Methods. Three parameters are used to identify a certain population, namely freeze-in temperature, relative abundance, and kappa value (κ), which together describe the potential non-Maxwellian kappa distributions of coronal electrons. Our method chooses the reduced chi-squared to describe the goodness of fit of the model to the observations. The parameters of our model are optimized with the covariance-matrix-adaptation evolution strategy (CMA-ES). Results. Two major types of ICMEs are identified according to the existence of hot material, and both, that is, the cool type and the hot type, have two main subtypes. Different populations in those types have their own features related to freeze-in temperature and κ. The electron velocity distribution function usually contains a significant hot tail in typical coronal material and hot material, while the Maxwellian distribution appears more frequently in mid-temperature material. Our model is also suitable for all types of solar wind and the existence of hot populations as well as the change of temperatures of individual populations may indicate boundaries between ICMEs and individual solar wind streams.

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Statistical Study of ICMEs with Low Mean Carbon Charge State Plasmas Detected from 1998 to 2011

Cited by 9 publications

References 52 publications

Solar Cycle Dependence of ICME Composition

Solar Cycle Dependence of ICME Composition

Key Signatures of Prominence Materials and Category of Cold Materials Identified by Random Forest Classifier

Detailed composition of iron ions in interplanetary coronal mass ejections based on a multipopulation approach

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